Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, video, and the like, and deployments are likely to increase with introduction of new data oriented systems such as Long Term Evolution (LTE) systems. Wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, 3GPP Long Term Evolution (LTE) systems, and other orthogonal frequency division multiple access (OFDMA) systems.
Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals (also known as user equipments (UEs), user terminals, or access terminals (ATs)). Each terminal communicates with one or more base stations (also known as access points (APs), EnodeBs, or eNBs) via transmissions on forward and reverse links. The forward link (also referred to as a downlink or DL) refers to the communication link from the base stations to the terminals, and the reverse link (also referred to as an uplink or UL) refers to the communication link from the terminals to the base stations. These communication links may be established via single-in-single-out, single-in-multiple out, multiple-in-single-out, or multiple-in-multiple-out (MIMO) systems.
Newer multiple access systems, for example, LTE, deliver faster data throughput than older technologies. Faster downlink rates, in turn, have sparked a greater demand for higher-bandwidth content, such as high-resolution graphics and video, for use on or with mobile devices. Therefore, demand for bandwidth on wireless communications systems continues to increase despite availability of higher data throughput over wireless interfaces, and this trend is likely to continue. However, wireless spectrum is a limited and regulated resource. Therefore, new approaches are needed in wireless communications to more fully utilize this limited resource and satisfy consumer demand.